Thallium Strontium Iodide: A High Efficiency Scintillator for Gamma-ray Detection.

Europium-doped TlSr2I5 (TSI), a new high light yield scintillator for gamma-ray detection, has been grown by the vertical Bridgman method. A 12mm and 16mm diameter boules of TSI is grown in a two-zone vertical furnaces. Samples extracted from the grown boule have been characterized for their scintillation properties. Energy resolution of < 3% (FWHM) at 662 keV and a gamma-ray light yield of approximately 54,000 Ph/MeV have been obtained. Decay times of 395 ns (89%) and 2.0 microseconds (11%) have been measured.